Engine.



T. S. MILLER.

ENGINE.

APPLICATION FILED SEPT. 10, 1907.

Patented June 4, 1912.

2 SHBETS SHEBT 1.

T. s; MILLER.

ENGINE.

APPLICATION FILED SEPT. 10, 1907.

1,028, 127. Patented June 4, 1912.

2 SHEETS-SHEET 2.

THOMAS SPENCER MILLER, OF SOUTH ORANGE, NEW JERSEY.

ENGINE.

Specification of Letters Patent.

Patented June a, 1912.

Application filed September 10, 1907. Serial No. 392,115.

To all whom it may concern:

Be it known that I, THOMAS SPENCER.

MILLER, a citizen of the United States, and a resident of South Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Engines, of which the following is a specification.

This invention relates to certain novel and useful improvements in engines and has particular application to an engine for operating a cable, rope or the like.

The invention consists in the improvements to be fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

I have fully and clearly illustrated my invention in the accompanying drawings to be taken as a part of this specification and wherein Figure 1 is a plan view of a structure embodying my invention. Fig. 2 is a view in side elevation of the construction shown in Fig. 1. Fig. 8 is a view in longitudinal section through a controlling valve for the engine illustrated in Figs. 1 and 2. Fig. 4 is a section on the line 4t of Fig. 3. Fig. 5 is a section on the line 5-5 of Fig. 3.

In the embodiment of the invention se lected for the purposes of illustration, the engine is illustrated as constituting means for driving a rope winding drum and, as illustrated, said engine comprises preferably a pair of cylinders provided with a common crank shaft, upon which the winding drum is mounted.

As is well known, two engines working with cranks set at 90 will vary considerably in power at various positions of the cranks. The maximum pull on the rope on the reel may be, for example, 3000 lbs., at one position of the two cranks, and only 2000, lbs. at another position. In one revolution of the crank shaft, there will be four points of maximum crank efiort, for instance, 3000 lbs. rope pull, and four points of minimum crankeffort, say 2000 lbs. rope pull, spaced about 45 apart. The torque is not uniform, but when theengines are in motion, that is, at considerable speed, the momentum of the parts may be sufficient to bridge over these variations of useful effort and in the end produce very nearly uniform pull. Experiments show that with the engine turning very slowly the change in the rope pull is evidenced by the resulting variation of sag or deflection of the rope. I propose, therefore, to produce a reel or engine of uniform torque, which end I accomplish by altering the steam pressure on the engine. That is to say, when the cranks are at maximum effort, the steam pressure will be reduced, while when the cranks are at minimum effort, the steam pressure will be increased. The amount of increase of steam pressure on the one hand and the decrease of steam pressure on the other will tend to equalize the rope pull and pro duce a uniform torque.

In Fig. 3 I have shown a cross section of a valve which embodies the combination of a reversing valve and a steam pressure regulating valve. This valve is used in connection with my engine or reel in which latter 15 designates the frame or bed plate, 16 the rope drum or reel, 17 the crank, and 1818 the double cylinders of the engine from which the crank shaft is driven, said cylinders having the usual D-slide valves (not shown) driven from eccentrics 18 18" on the crank shaft by the usual rod connections (not shown).

In the regulating and reversing valve R the steam from the boiler enters at the port P to the valve steam chest (4. The position of the D slide valve S shown in Fig. 3 is for the forward running of the engine and that position in which the steam in the cylinders holds the drum against paying out of the rope tending to wind the same on the drum. The steam passes from the steam chest a through the port I), thence through the port 6 to the chamber d, when the valve 0 is open, the valve 0 being urged toward its seat by the pressure of the spring 7L and to Open position by the spring it. From chamber (Z the steam passes through the pipe 0 to the chests of the D-slide valves of the respective engine cylinders. The exhaust steam from the exhaust ports of the cylinders passes through the pipes f to the valve R to the port f to the exhaust chamber f and the exhaust pipe 9. To reverse the engine to cause it to pay out the rope, the valve S is shifted by throwing the lever L to the left-to bridge the ports I) and f. The live steam now passes from the chest a through the port f through the pipes f to the exhaust ports of the cylinders. The exhaust steam in this position of the valve S enters the valve R by way of the pipe 0, connected to the engine valve chests, thence to the exhaust pipe 9 by way of the port I) and the exhaust chamber f. When the engine is reversed lever 20 is moved to the left to compress spring h to the limit, thus unseating valve 0 at b and establishing communication between (Z and Z). The regulation of the steam pressure admitted to the cylinders (for the forward running) is effected by the pressure of the spring h which is set to a determined tension. The spring pressure of the spring h is altered by a movement to the right or left of the plunger H. The spring h. at its left end abuts against the piston E, which piston forms the seat for the right-hand end of the hollow valve 0 Opening into the exhaust g and closing the passage through said valve. The valve G is kept sealed at b by a light spring 72. when the spring 72 is relaxed or is balanced by steam pressure. The steam admitted to the cylinders may be varied from boiler pressure to zero, by means of this regulating valve. The action is as follows: For the purposes of explanation, suppose the boiler pressure to be 150 lbs. and the spring h compressed to open the valve C to admit steam to the cylinders whenever the pressure in the cylinders drops below 100 pounds. The valve C being unseated through the action of the spring 72. the steam passes from a through Z) into the pipes and cylinders. When suilicient steam has passed through to bring the pressure in the cylinders up to 100 lbs. the steam acting on the piston E through the hollow valve C will balance the pressure of the spring h tending to open the valve, and the valve C will immediately be seated and no more steam is permitted to pass through as long as the cylinder pressure and spring pressure are balanced. As the steam is used by the engine, however, the pressure in the cylinders will be reduced and the valve C will be opened by the spring 72. to admit more steam from the boiler to keep up the desired pressure. So it will be noted that there is a constant movement of the valve C which remains open just long enough to permit suflicient steam to pass into the engine to compensate for that used by the engine and always maintains a pressure proportional to the pressure of the spring h.

In order to produce a uniform torque I employ the above described regulating valve to increase the pressure of steam admitted to the engine at the four points of minimum crank effort and decrease the pressure at the four points of maximum crank effort. The steam pressure is varied in the same proportion as the crank effort varies. To effect this four-fold variation of pressure I employ a cam (which may be placed upon one of the flanges of the drum) on the engine crank shaft, having four elevated portions and four depressed portions corresponding to the points of minimum and maximum crank efiort respectively. In contact with the cam is a roller 76 mounted upon the arm is secured to the rock shaft k The arm is also secured to the shaft 70 and communicates the movement of the roller 71: through the links at and n and the plunger H to the spring h.

By means of the lever 20 the link 21, the bell crank 22 and link 28 pivoted at its upper end to the intersection of the links m and n the normal pressure of the spring b may be manually varied to determine the steam pressure to be maintained in the cyl' inders. This does not eifect the fourfold variation produced by the cam j, but only determines the normal working pressure to be maintained by the regulating valve. For example, I suppose the steam pressure is varied during the revolution of from 80 to 120 pounds by the cam j; the normal working pressure is 100 pounds and the range of variation is 40 pounds. Now, it the lever 20 be thrown to the left the spring h will be relaxed and the four-fold steam pressure variation will be from L0 to 80 poundsthe normal working pressure now being 60 pounds, but the range of variation remains unchanged, or 40 pounds.

As heretofore stated, this engine is particularly adapted for use in connection with marine cableways, and in this use the engine is operated as follows: The engine and drum with a line wound thereon is mounted on a vessel and the line is connected to the other vessel and the valve S is shifted to the left of the position shown in Fig. 3 so that the steam inlet is connected to the exhaust ports of the engine valves. The engine then runs to cause the drum topay out the rope. lVhen the proper amount of rope has been paid out the valve S is then placed in the position shown in Fig. 3 when the engine operates to take up the rope to raise it to the proper elevation. This winding of the rope continues until the force of the rope pull on the cylinder pistons substantially equals the steam pressure on the pistons determined by the force of 'the spring h holding the valve G open, and this pres sure acting on the head E permits the valve C to be closed by the spring h, and the pressure on the valve which cuts off the supply of steam to the cylinders. VJ hen the valve G is closed the steam in the cylinders is on but one side of the pistons and acts as a cushion to oppose the movement of the pistons under force of the rope pull. Should for any reason the tension on the rope be unduly increased the pistons will be moved to compress the steam held in the cylinders, thereby increasing the pressure of the steam in the cylinders and on the head E; this increase, if it be above that determined by the spring 71,, will act on the head E to move the latter back from the rear end of the valve C, opening the bore of the latter to the exhaust to permit the excess pressure in the cylinders to escape, which continues until the pressure is sufficiently reduced to permit the head E to again engage the rear end of the valve 0. This let-off of the pressure when the drum is overhauled permits the drum to let out enough rope to let the cable drop to its normal position. If the cable should slack off so as to enable the steam pressure to overcome the pull of the cable, then the engine will run forward to take up the slack, again automatically stopping when the pull approximately equals the steam pressure.

It will be understood that normally this engine holds the rope at a certain deflection; that is, as long as the rope is at the proper deflection, the engine does not operate to revolve the crank shaft but merely opposes the strain exerted by the pull on the rope. If the drum is pulled by the rope to a point where one of the cams operates through the plunger H, spring h and head E to open the valve, then steam will be admitted to the cylinders so as to supplement the normal pressure to augment the crank effort so that the resistance to the pull on the rope by the en gine or to the holding strength of the latter will be substantially the same when the cranks are in the least effective position as when in most effective position. When the cranks are in most effective position the plunger H will be moved away from the valve so that the pressure in the cylinders will be maintained at substantially that determined by the regulation of the spring 72 It will be understood, however, that the valve will be similarly operated with like effect when the drum is being revolved in either direction to take up or let out the rope; that is, the valve will control the engine pressure to produce a uniform torque on the crank shaft.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. The combination of a multiple cylinder fluid operated engine, pistons in the cylinders, cranks operated by the pistons of said engine, said cranks being set at an angle to one another, valve mechanism for varying the pressure of the fluid in the cylinders of said engine, and means whereby the valve is operated to cause the fluid pressure to increase when the cranks are in their least effective position and to reduce the pressure in the cylinders when said cranks are in their most effective position.

2. In a double cylinder fluid-operated engine, pistons in the cylinders, cranks operated by said pistons and set at an angle to one another, valve mechanism for varying the pressure of the fluid in the cylinder of said engine, and means for automatically operating the valve mechanism, whereby the pressure will be maximum when the cranks are at their least efficient position, and minimum when the cranks are at their most efficient position.

3. The combination of a multiple cylinder fluid operated engine, pistons in the cylinders, cranks driven by said pistons, valve mechanism for varying the pressure of the fluid in the cylinders of said engine, and means for operating the valve mechanism to increase the fluid pressure four times, and to decrease it four times during one complete revolution of the cranks.

l. The combination of a multiple cylinder fluid operated engine, pistons in the cylinders, cranks operated by the pistons, valve mechanism for varying the pressure of the fluid in the cylinders of said engine, and means controlled by the posit-ion of the cranks for operating the valve mechanism to increase the fluid pressure four times,'and to decrease it four times during one complete revolution of the cranks.

5. In an engine, the combination of a fluid pressure cylinder, a piston therein, a crank mechanism actuated by the piston, fluid supply means for the pressure cylinder, and means wholly self-contained within the engine structure for actuating the fluid supply means whereby uniform torque is produced on the crank driving mechanism.

6. In an engine, the combination of a fluid pressure cylinder, a piston in the cylinder, a crank mechanism actuated by the piston, fluid supply means for the pressure cylinder, and means driven by the crank mechanism and cooperating with the fluid supply means to operate the latter to cause a minimum supply of fluid when the crank mechanism is in its most efficient position and a maximum supply of fluid when the crank mechanism is in its least efficient position.

7. In an engine, the combination of a fluid pressure cylinder, a piston in the cylinder, a crank mechanism actuated by the piston, fluid supply means for controlling the sup .ply of pressure to the pressure cylinder, and

means operated by the crank mechanism and cooperating with the fluid supply mechanism to operate the latter to increase the supply when the crank mechanism is in its least effective position and to reduce the supply when the crank mechanism is in its most eflective position.

8. In an engine, the combination of a fluid pressure cylinder, a piston in the cylinder, a crank mechanism actuated by the piston, fluid supply means for controlling the supply of pressure to the cylinder, and means operated by the crank mechanism and cooperating with the fluid supply mechanism to increase the supply of fluid to the pressure cylinder when the crank mechanism is in its least effective position.

9. In an engine, the combination of a fluid pressure cylinder, a piston in the cylinder, a crank mechanism actuated by the piston, fluid supply means for regulating the supply of pressure to the pressure cylinder, and a cam operated by the crank mechanism and engaging the fluid pressure mechanism to actuate the latter to increase the fluid supply when the cranks are in their least effective position whereby uniform torque of the drum is produced.

10. In an engine, the combination of a plurality of fluid pressure cylinders, pistons in the cylinders, a crank shaft having cranks set at angles to each other and driven by the said pistons, fluid supply mechanism for controlling the supply of fluid pressure to the cylinders, and means associated with the crank shaft arranged to actuate the fluid supply mechanism when the cranks are in their least effective position to increase the fluid supply to the cylinders whereby a uniform power effort of the crank shaft is produced.

11. In combination, an engine cylinder, a piston, a crank driven by the piston, a cylinder valve, a regulating valve for admitting steam to the cylinder valve, a spring set to open the regulating valve upon a determined reducticn of steam in the cylinder, and means for regulating the force of the spring.

12. In combination, an engine cylinder, a piston, a crank driven by the piston, a cylinder valve, a regulating valve for admitting steam to the cylinder valve, a spring set to open the regulating valve upon a determined reduction of steam in the cylinder, means for regulating the force of the spring, and means whereby the force of the spring is opposed by the pressure in the cylinder.

13. In combination, an engine cylinder, a piston, a crank driven by the piston, a cylinder valve, a regulating valve for admitting steam to the cylinder valve, a spring set to open the regulating valve upon a determined reduction of steam in the cylinder, and means operable by the cranks for regulating the force of the spring.

lat. In combination, an engine cylinder, a

piston, a cylinder valve, a crank driven by the piston, a regulating valve for admitting pressure to the cylinder valve chest, and means driven by the crank shaft for actuating the regulating valve to admit steam at the least effective portion of the crank movement.

15. In combination, an engine cylinder, a piston, a cylinder valve, a crank shaft driven by the piston, a regulating valve for admitting pressure to the cylinder, means for automatically opening the regulating valve upon a reduction of pressure in the cylinder, and means driven by the crank shaft for automatically opening the regulating valve irrespective of the reduction of pressure in the cylinder.

16. In combination, an engine cylinder, a piston in the cylinder, a cylinder valve, a

crank driven by the piston, a regulating valve for admitting fluid pressure to the cylinder, a spring for automatically opening the valve against the cylinder pressure, means for regulating the force of the spring, and means for increasing the force of the spring at the least effective portion of the crank movement.

17. In combination, an engine cylinder, a piston in the cylinder, a cylinder valve, a crank driven by the piston, a regulating valve for admitting fluid pressure to the cylinder, a spring for automatically opening the valve against the cylinder pressure, means for regulating the force of the spring, and means for increasing and decreasing the force of the spring at points corresponding respectively to the least effective and most effective portions of the crank 1novement.

18. In combination, an engine cylinder, a piston, a cylinder valve, a crank shaft driven by the piston, a regulating valve for admitting fluid pressure to the cylinder, a spring for opening the valve against the cylinder pressure, means for regulating the spring pressure, and means driven by the crank shaft for increasing the force of the spring at the least effective portion of the crank movement.

19. In combination, an engine cylinder, a piston, a cylinder valve, a crank driven by the piston, a regulating valve for admitting. pressure to the cylinder, a spring normally acting to open said regulating valve and exposed to cylinder pressure, to oppose its valve opening movement, means for regulating the force of said spring to open the valve upon a reduction of pressure in the cylinder below a determined point, and means acting automatically at the least effective portion of the crank movement to increase the spring force.

In testimony whereof, I hereunto sign my name in presence of two subscribing Witnesses.

THOMAS SPENCER MILLER.

Vitnesses:

ERNEST PULSFORD, S. G. Rosanne.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

